2,335 research outputs found
The Dynamical Dipole Mode in Fusion Reactions with Exotic Nuclear Beams
We report the properties of the prompt dipole radiation, produced via a
collective bremsstrahlung mechanism, in fusion reactions with exotic beams. We
show that the gamma yield is sensitive to the density dependence of the
symmetry energy below/around saturation. Moreover we find that the angular
distribution of the emitted photons from such fast collective mode can
represent a sensitive probe of its excitation mechanism and of fusion dynamics
in the entrance channel.Comment: 5 pages, 3 figures, to appear in Phys.Rev.
The Dynamical Dipole Mode in Dissipative Heavy Ion Collisions
We study the effect of a direct Giant Dipole Resonance () excitation in
intermediate dinuclear systems with exotic shape and charge distributions
formed in charge asymmetric fusion entrance channels. A related enhancement of
the gamma yield in the evaporation cascade of the fused nucleus is
expected. The dynamical origin of such extra strength will show up in a
characteristic anisotropy of the dipole gamma-emission. A fully microscopic
analysis of the fusion dynamics is performed with quantitative predictions of
the photon yield based on a dynamics- statistics coupling model. In
particular we focus our attention on the energy and mass dependence of the
effect.
We suggest a series of new experiments, in particular some optimal entrance
channel conditions. We stress the importance of using the new available
radioactive beams.Comment: 20 pages (Latex), 14 Postscript figure
Computing Heavy Elements
Reliable calculations of the structure of heavy elements are crucial to
address fundamental science questions such as the origin of the elements in the
universe. Applications relevant for energy production, medicine, or national
security also rely on theoretical predictions of basic properties of atomic
nuclei. Heavy elements are best described within the nuclear density functional
theory (DFT) and its various extensions. While relatively mature, DFT has never
been implemented in its full power, as it relies on a very large number (~
10^9-10^12) of expensive calculations (~ day). The advent of leadership-class
computers, as well as dedicated large-scale collaborative efforts such as the
SciDAC 2 UNEDF project, have dramatically changed the field. This article gives
an overview of the various computational challenges related to the nuclear DFT,
as well as some of the recent achievements.Comment: Proceeding of the Invited Talk given at the SciDAC 2011 conference,
Jul. 10-15, 2011, Denver, C
Star-forming galaxies versus low- and high-excitation radio AGN in the VLA-COSMOS 3GHz Large Project
We study the composition of the faint radio population selected from the
VLA-COSMOS 3GHz Large Project, a radio continuum survey performed at 10 cm
wavelength. The survey covers the full 2 square degree COSMOS field with mean
Jy/beam, cataloging 10,899 source components above . By combining these radio data with UltraVISTA, optical, near-infrared,
and Spitzer/IRAC mid-infrared data, as well as X-ray data from the Chandra
Legacy, and Chandra COSMOS surveys, we gain insight into the emission
mechanisms within our radio sources out to redshifts of . From these
emission characteristics we classify our souces as star forming galaxies or
AGN. Using their multi-wavelength properties we further separate the AGN into
sub-samples dominated by radiatively efficient and inefficient AGN, often
referred to as high- and low-excitation emission line AGN. We compare our
method with other results based on fitting of the sources' spectral energy
distributions using both galaxy and AGN spectral models, and those based on the
infrared-radio correlation. We study the fractional contributions of these
sub-populations down to radio flux levels of 10 Jy. We find that at
3 GHz flux densities above 400 Jy quiescent, red galaxies,
consistent with the low-excitation radio AGN class constitute the dominant
fraction. Below densities of 200 Jy star-forming galaxies begin to
constitute the largest fraction, followed by the low-excitation, and X-ray- and
IR-identified high-excitation radio AGN.Comment: 7 pages, 3 figures, The many facets of extragalactic radio surveys:
towards new scientific challenges, Bologna 20-23 October 201
Centrality Dependence of Thermal Parameters Deduced from Hadron Multiplicities in Au + Au Collisions at sqrt{s_{NN}} = 130 GeV
We analyse the centrality dependence of thermal parameters deduced from
hadron m ultiplicities in Au + Au collisions at .
While the chemical freeze-out temperature and chemical potentials are found to
be roughly centrality-independent, the strangeness saturation factor
increases with participant number towards unity, supporting the assumption of
equilibrium freeze-out conditions in central collisions
All-trans retinoic acid release from biodegradable polyester microcapsules
[Excerpt] Tissue engineering strategies frequently include a scaffold, living cells and bioactive substances to promote cell growth and guide cell differentiation. The encapsulation in carriers enables protects
the bioactivity of those substances upon implantation, avoids being transported by the body fluids and also allows controlling the release rate. Encapsulation materials are preferably biodegradable
polymers. In this work, all-trans retinoic acid (atRA) was used as a model bioactive agent; since it was shown that atRA enhances the expression of osteocalcin, a specific osteogenic marker. [...]info:eu-repo/semantics/publishedVersio
A simple and efficient numerical scheme to integrate non-local potentials
As nuclear wave functions have to obey the Pauli principle, potentials issued
from reaction theory or Hartree-Fock formalism using finite-range interactions
contain a non-local part. Written in coordinate space representation, the
Schrodinger equation becomes integro-differential, which is difficult to solve,
contrary to the case of local potentials, where it is an ordinary differential
equation. A simple and powerful method has been proposed several years ago,
with the trivially equivalent potential method, where non-local potential is
replaced by an equivalent local potential, which is state-dependent and has to
be determined iteratively. Its main disadvantage, however, is the appearance of
divergences in potentials if the wave functions have nodes, which is generally
the case. We will show that divergences can be removed by a slight modification
of the trivially equivalent potential method, leading to a very simple, stable
and precise numerical technique to deal with non-local potentials. Examples
will be provided with the calculation of the Hartree-Fock potential and
associated wave functions of 16O using the finite-range N3LO realistic
interaction.Comment: 8 pages, 2 figures, submitted to Eur. Phys. J.
The walking robots critical position of the kinematics or dynamic systems applied on the environment model
© 2018 Authors. The exposure is dedicated in the first to mathematical modeling of the environment where the aspects on the walking robots evolution models are described. The environment's mathematical model is defined through the models of kinematics or dynamic systems in the general case of systems that depend on parameters. The important property of the dynamic system evolution models that approach the phenomenon from the environment is property of separation between stable and unstable regions from the free parameters domain of the system. Some mathematical conditions that imply the separation of stable regions from the free parameters domain of the system are formulated. In the second part is described our idea on walking robot kinematics and dynamic models with aspects exemplified on walking robot leg. An inverse method for identification of possible critical positions of the walking robot leg is established
Variation in Outcome Reporting in Studies of Fertility-Sparing Surgery for Cervical Cancer: a Systematic Review.
BACKGROUND: Cervical cancer affects 3,197 women in the UK, and 604000 women worldwide annually, with peak incidence seen between 30-34 years of age. For many, fertility-sparing surgery is an appealing option where possible. However, absence of large-scale data, along with a notable variation in reported outcomes in relevant studies may undermine future efforts for consistent evidence synthesis. OBJECTIVES: To systematically review the reported outcomes measured in studies that include women who underwent fertility-sparing surgery for cervical cancer and identify whether variation exists. SEARCH STRATEGY: We searched MEDLINE, EMBASE, and CENTRAL from inception to February 2019. SELECTION CRITERIA: Randomised controlled trials, cohort and observational studies, and case studies of more than 10 participants from January 1990 to date. DATA COLLECTION AND ANALYSIS: Study characteristics and all reported treatment outcomes. MAIN RESULTS: 104 studies with a sum of 9535 participants were identified. Most studies reported on oncological outcomes (97/104), followed by fertility and pregnancy (86/104), post-operative complications (74/104), intra-operative complications (72/104), and quality of life (5). There were huge variation and heterogeneity in reported outcomes, with only 12% being good quality and 87% being of poor quality. CONCLUSIONS: There is significant heterogeneity in the reported outcomes. An agreed Core Outcome Set (COS) is necessary for future studies to effectively harmonise reported outcomes that are measurable and relevant to patients, clinicians, and researchers. This systematic review sets the groundwork for the development of a COS for fertility-sparing surgery in cervical cancer
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